Upper receiver for a firearm



FIG. 1 is a top plan view of a first exemplary embodiment of the upper receiver for a firearm, showing my new design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a front view thereof;

FIG. 6 is a rear view thereof;

FIG. 7 is an upper, right front perspective view thereof;

FIG. 8 is an upper, right rear perspective view thereof;

FIG. 9 is an upper, left front perspective view thereof;

FIG. 10 is an upper, left rear perspective view thereof;

FIG. 11 is a lower, right rear perspective view thereof;

FIG. 12 is a lower, left rear perspective view thereof;

FIG. 13 is an lower, left front perspective view thereof; and,

FIG. 14 is a lower, right front perspective view thereof. 

CLAIM The ornamental design for an upper receiver for a firearm, substantially as shown and described. 